Apparatus and method for spot-coating sheet and web materials

ABSTRACT

A method of and apparatus for accurately and rapidly spot or continually coating either sheet or weblike materials, to place a protective and/or functional coating thereon. A photoelectric or other control mechanism triggers the deposition of the coating material through an &#39;&#39;&#39;&#39;antidrool&#39;&#39;&#39;&#39; valve and nozzle arrangement after which the coated areas may be smoothed or otherwise deformed such as, for example, to form lenticulated lenses on the surface of the coating. These subsequent forming or deformation steps may, of course, be omitted if only very minute amounts of the coating are being deposited or if contoured or patterned surface areas are desired.

O Unite States Patent 11 1 3,607,340

[72] Inventor Herman F. Stroupe [56] [References Cited Azlingwn UNITEDSTATES PATENTS P 2 326 3,056,337 10/1962 Bahret al. 118/2 x [22] F1ledApr. 6,1970 3 241429 3/1966 l 0 d Se L21 1971 Ice eta 117/1 X pncmc p 3315 399 4/1967 Qua v 239/586 [73] Assignee Eastman Kodak Company r eRochesterN 3,317,334 5/1967 Norton.... 117/64 X Continuation ofapplication Ser. No. 6/1967 Talbo? l 645,675June 13) 1967mm apandom1/1969 Guthrle 118/2 Primary Examiner-Ralph S. Kendall ABSTRACT: Amethod of and apparatus for accurately and rapidly spot or continuallycoating either sheet or weblike APPARATUS AND METHOD FOR SPOT COATINGfitlatenalsl,A toh placle a protective and/o1; fufliltimflfll coatmgSHEET AND WEB MATERIALS ereon. p otoe ectric or ot er contro mec amsmtriggers he de osltion of the coatin materlal throu h an ant1drool"10Cla1ms 8Drawin Fi s t p g g g g valve and nozzle arrangement afterwhich the coated areas [52] US. Cl 117/10, may be smoothed or otherwisedeformed such as, for example, 117/37,117/64,117/120,ll8/2,1l8/8,ll8/407to form lenticulated lenses on the surface of the coating. [51] Int. ClB05c 3/18, These subsequent forming or deformation steps may, of B05011/00 course, be omitted if only very minute amounts of the coating [50]Field of Search 1 18/407, 2, are being deposited or if contoured orpatterned surface areas are desired.

PRINTING COATING FORMING E, E,S

AND/0R MELT AND/0R (OPTIONAL) STACK'NG 0R STACK OR FLUID suPPDr SINGLE0R ROLLING AND/ ROLL SUPPLY 1 SYSTEM- MULTIPLE P03 1 OR TRANSFER FEEDING1 TIME DELAY OR 1 WONT-SPREAD l) FOR ADDITIONAL COMPUTOR ING AND/ORTREATMENT I CONTROLLED DEFORMING 1| 1 l 1 1 1 1 I I I 1 l 1 1 l 1INTERMEDIATE 1 I FEEDING l l l 1 ROLL, CYLINDER,

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ATTORNEY 8k AGENT PATENTEU sEP21 I9?! SHEEI 3 BF 5 Hermon FE StroupeINVENTOR.

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sumunrs ll I i a a I Herman E Stroupe INVENTOR.

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Hermon F. Stroupe INVENTOR.

ATTORNEY Bu AGENT APPARATUS AND METHOD FOR SPOT-COATING SHEET AND WEBMATERIALS This application is a streamlined continuation of Stroupe U.S.Ser. No. 645,675, filed June 13, 1967 now abandoned.

This invention relates to a new method and apparatus for economicallyand accurately coating selected areas on a moving surface or plane. Moreparticularly, the invention relates to spot coating a surface withapparatus having incorporated therein an antidrool valve similar to thatdescribed in Quarve US. Pat. No. 3,315,899 dated Apr. 25, 1967.

Most prior art concepts and devices suggested for use in coating varioussurfaces employ either roll or spray applicators. Neither of thesesystems has been fully satisfactory for the application of plastic orother viscose materials for several reasons, and it is the prime objectof this invention to provide a method and means to accomplish this end.

As can be appreciated, the roll application of coating materials, andparticularly plastic coatings, has been severely limited because thecoating cylinder design must include adequate control apparatus as wellas specially designed and etched roll plates. Additionally, if it isdesired to deform the coated surface, the impression or compressionrolls must be provided with recessed grippers to allow for the accurateand controlled gripping of the sheet material without interference withthe associated rolls. The rolls system is further limited to dry inktreatments which obviously require undesirable delays between theprinting and coating of stock material.

Neither roll nor spray systems can be relied upon to deposit a uniformcoating and a clean startup and cutoff is practically unattainable.Therefore, a further limitation of small printed areas on relativelylarge sheets is necessary in order to catch the excess spillover ofcoating material inherent with these applicators. These techniquesfurther require that specific coating and substrate materials be used inorder to obtain the necessary thicknesses, adherence, and freedom fromcobweb formations, all of which are limiting and costly factors withinthe coating field.

According to this invention a method and apparatus is pro vided fordeposition of a fluent or fluidlike coating, and in particular plasticmaterial coatings, upon a variety of substrate materials, thus providingeither a protective or functional final coating thereon. The system andmethod employed involves the use of at least a single, and generally aplurality of antidrool type valve and nozzle arrangements with which thecoating material is controlled. Upon receipt of control signals, thesevalves will accurately startup or cutoff with minimal tailing because ofthe vacuum and holding action that is effective during a selected partof their operating cycle.

Therefore, one object of this invention is the elimination of the needfor a special roller-type coating mechanism employ ing recessed grippersand other necessary and special design features as above noted.

Another object of this invention is to provide a simplified method andapparatus which will allow, in sheet or roll coating applications, anintermittent deposition of a coating over a specified area of substratematerial with the assurance that only the predesignated area will be sotreated.

Yet another object of this invention is to provide a method andapparatus which will not only allow particular areas of either the sheetor web material to be accurately coated, but will also permit theproduction of contoured areas as well.

Further objectives of this invention include:

I. the design of manifold-type valve and nozzle systems so that thecoating apparatus can easily accommodate different sheet or web sizeswithout extensive modifications being made to the equipment;

2. making possible the deposition of a coating of practically unlimitedand uniform thicknesses; and

3. simplifying the installation and modification steps involved insetting up a typical printing press for use with the disclosed processand apparatus.

These and further objectives and advantages of the present inventionwill become more apparent upon reference to the following description,claims, and appended drawings wherein:

FIG. 1 is a simplified flow diagram outlining the various method stepsof the invention;

FIG. 2 is a schematic diagram of a preferred embodiment of the apparatusintended to carry out the method of the invention;

FIG. 3 is a schematic diagram of another embodiment of the apparatuswhich may be used to carry out the method of the invention and in whichthe substrate material has a substantially straight line flow-path;

FIG. 4 is a schematic diagram of a representative control system whichmay be used with and incorporated in the apparatus of the invention;

FIG. 5 is a simplified schematic diagram ofa typical timing circuitwhich may be used in controlling the coating operation;

FIG. 6 is a perspective view of one of the valve and nozzle arrangementsused in the coating apparatus;

FIG. 7 is a cross section taken along lines 7-7 of FIG. 6; and

FIG. 8 is a bottom view of the valve and nozzle arrangements as shown inFIG. 6.

With continued reference to the accompanying figures wherein likereference numerals designate similar parts throughout the various views,and with initial attention directed to FIG. I which illustrates thegeneral method of the invention, it can be seen that the use ofsubstrate materials, which may be printed or unprinted and in eithersheet or roll form is contemplated.

The method further contemplates the possibility of intermediate storageprior to the coating operation, and therefore it may be necessary tofeed to the coating zone from a stacked formation of the substrate. Themultiple capabilities of this system thus presents a versatile overallmethod of coating in addition to achieving the prime objective of theinvention; that being the development of a satisfactory spotcoatingmethod which is either adaptable to existing equipment or easilymanufactured as an integral self-contained unit.

From the as stored area, or in an in-line operation, the substratematerial used in practicing this invention is fed to a coating zone inwhich the presence of the material or the area thereon to be coated issensed and the depositing system is activated. After deposition, theinherently beaded formation is evenly spread so that the entire area tobe coated is uniformly covered. Immediately thereafter, or inconjunction therewith, the coated area may be deformed in any patterndesired after which the coated substrate is forwarded to anotherstacking mechanism. Of course, should it be so desired, the substratemay be rerolled or forwarded to subsequent treatment areas such as, forexample, cutting and slitting stations where the coated stock may betrimmed to size.

In addition to the above, certain aspects of the invention anticipatethe desirability of leaving a beaded or layered formation upon thesubstrate material without the performance of any subsequent formingsteps. This would result in the formation of a predetermined design,configuration, or contoured shape.

It is unnecessary in the practiceof the invention that a completelyintegral single line system be used. A partial system where thesubstrate is transferred from stack to stack with intermediate coatingmay at times be desirable or necessary. In such cases the feedingmechanism will remove a particular sheet, or the web material, from itsrespective stack or roll, pass it through the coating area to thesmoothing and deforming station, and it will subsequently be recollectedin its original form, assuming no further treatment is desired.

As will be appreciated, this invention is readily adaptable for use withpractically all fluent materials, including plastics, inks, dyes, orother suitable fluids which are applicable to being applied as aspot-coating. However, for sake of illustration, particular emphasis ishereinafter placed upon the use of plastic materials as the coatingmedia. Likewise, any number of suitable substrate materials such aspaper, ceramics, cloth, wood, metals or the like may be used inpracticing this invention. However, for illustrative purposes,particular emphasis will be placed hereinafter upon the use of papersubstrates.

As will be apparent to those skilled in the art, the invention can beused in decorative and/or functional applications. Decorativeapplications most commonly employ the use of inks, dyes, or othersimilar fluids, whereas for functional and protective purposes waxes,plastics, or the like will normally be employed. Functional usesinclude, for example, lenticulated surfaces, contoured surfaces, braillesystems, and computer tapes and cards, any or all of which may requiredeformation during their formation. Of course, in protectiveapplications it is only necessary to thinly, evenly, and smoothly coatthe substrate material.

In a preferred embodiment of the apparatus encompassing the invention. afluent or plastic melt storage and pumping system is attached to amodified printing press generally designated as 12. Within this press islocated a sheet stacker 14 containing paper or other substrate sheetmaterials I which may be grasped by the suction device 16 andtransferred to the belt and roll feed systems 18. As a sheet 1 isforwarded through the roll system 18, its presence is sensed by asensing means 20 such as a flag switch or photoelectric cell whichthereupon emits a signal to activate a timing or other delay mechanism22. The sheet 1 continues to be advanced and is grasped by gripperscontained upon compression cylinder 24 and is thus transferred beneathan antidrool valve and nozzle head 26, which will be more fullydescribed hereinafter, and through which the fluent material isdeposited upon any particular portion of the sheet 1.

After the deposition, a rod or roller 28 functions to smooth the beadedmaterial deposit preparatory to a transfer of sheet 1, to compressioncylinder 30. Cylinder 30 has a deforming surface 32 acting inconjunction with cylinder 24 to deform the coating into the particularconfiguration desired. A steam or water spray system 34, including asupply source 35, is directed upon a cylinder 30 in order to provide forthe easy release and transfer of the plastic coated substrate therefromand to takeoff cylinder 36. From cylinder 36 it can be seen that thesheet 1 will be grasped by the roller-chain delivery system 38 andsubsequently deposited upon the stacking mechanism 40. Both of thestackers l4 and 40 can be seen as being movable in the verticaldirection by any suitable powered means, so that multiple sheets may beadequately removed or deposited without difficulty.

Referring now to FIG. 5, it can be seen that a sensing means 20, forexample, the photoelectric cell shown will, in response to the presenceof a sheet or indicia thereupon, generate a signal to be received by atimer or delay device 22. The timer 22, of course, may be presetaccording to the speed of travel of the substrate material, the positionwhere the deposit is desired, and the size or length of the depositdesired. These variables being controlled therein, the timing mechanism22 will subsequently signal solenoid 27 which upon its activation willallow air or some other suitable activating media from a pressure source2I to enter valve 26. This will open the valve and effect a properlyplaced deposit of a plastic or other fluid material, from system 10,upon the substrate.

It should be recognized that this particular timing device and sensingmechanism may be replaced by any suitable computerized or like systemwhich may be made integral therewith. Where a computer 42 (FIG. 4) isadapted to the overall coating system, sheet or web feed, as well asfluid material deposition may be controlled by the computer itself.Template 44, card 46, tape 48 or other similar computer means may beemployed therewith.

One possible modification of the preferred embodiment contemplates theuse of roll-stock material which can be fed into and through the coatingsystem. This, of course, would be particularly adaptable to a system asshown in FIG. 3 wherein there is a generally straight-through flowpattern of the substrate within the apparatus as it is being coated.Again it should be noted that a feeding mechanism 18, in this case feedrolls, advance the material through a sensing area where sensor 20detects the substrate presence and activates a fluid control delaydevice 22. This control delay device in turn energizes the solenoid 27thus allowing for the deposit of the coating fluid supplied underpressure from the storage and feed system 10. After depositionintermediate feed rolls 52 advance the stock between the smoothing rolls50 and onward to the deforming rolls 24, 30. In a manner similar to thatpreviously described, stacked sheets may be fed through the system ofFIG. 3. For example, a stacker 14 or a direct feed from a printing press54 can be used to supply the sheets, either of which may replace theroll stock supply 13. In most cases it is conceived that printedmaterials of various forms will be coated by this method and apparatus.One specific item of particular interest are lineiform pictures whichwhen covered by a lenticulated plastic coating give a three-dimensionaleffect. These pictures would first be printed, then coated, and thecoating surface deformed as hereinbefore mentioned.

The "antidrool" valve and nozzle 26 system may be placed in tandem, [asis shown in phantom in FIG.3], along the path of movement of thesubstrate if a layering type effect is necessary or desirable. Thus, bysimply removing the smoothing rolls 50 and deforming rolls 24, 30, acontrolled countered effect can be given to the surface of the substratebeing passed through the tandem nozzle system. By employing a secondsupply system 10 and related conduit system, the second or added tandemnozzles could be supplied with a different fluid thus giving the addedcapability of placing different fluid in a laminate array or inalternate positions upon the substrate.

Referring again to FIGS. 2 and 5, it can be seen that the fluid feed andstorage may consist of an extruder 8 or other suitable feed meanscapable of depositing the fluent material to be used as the coat into astorage tank 6. From this holding reservoir, pump 5 transfers theviscose fluid through a piping or conduit system 4 to the valve 26. Dueto the viscosity of the materials generally being handled, such a systemmust be under a relatively high positive pressure, as for example, onthe order of 200 p.s.i.g.

Referring now to FIGS. 6, 7, and 8 where the valve and nozzle manifold26 used with the apparatus of the invention is more clearly depicted,one can see that, while using only a single valve 23, a plurality ofnozzle openings 19 can be supplied from the head 25 which has a fluidreservoir 33 therein. The nozzles I9 are preferably spaced approximately0.10 inch apart, but, of course, such spacing depends upon the orificesize, fluid viscosity, and pressure.

It will be obvious from the drawings that in order to get increasedlateral coverage it is only necessary to abut the ends of heads 25 inany suitable mounting upon the coater. These head lengths can range inlength from about 4 inches to I2 inches, but with increased fluidpressure, the length may be as much as 107 inches or more. As will beappreciated, these valve and manifold heads 25 are closely adjacent thesubstrate path and preferably are between 0.002 inch and 0.250 inchabove the substrate surface.

In FIG. 7 it can be seen that the fluent coating material enters valve26 at opening 35 and depending upon the position of valve stem 15 may beconducted via passages 17 to the reservoir 33 and nozzles 19. Valve stem15 is activated by the introduction of a hydraulic or some other fluidmedium through openings 29 and 31 which are at opposite ends of thecylinder 9. Piston 13 is connected to valve stem 15 and is free to ridewithin cylinder 9 between its upper and lower ends which are defined bycap 64 and valve body 23.

When piston 60 is in an intermediate or lower position, as is shown inFIG. 7, the pressurized fluid is allowed to enter at opening 35 and bedeposited through nozzles 19 as abovediscussed. However, as the piston60 and valve stem 15 move upward the headed portion 66 of the valve stementers the cylindrical area 62 of body 23 and shuts off the fluid flow.The upward movement of piston 60 is thereafter continued and because ofthis, a partial vacuum is created in reservoir 33 and nozzle 19, thuswithdrawing the tailings outside of the nozzle area into the reservoirthereby effecting a clean cutoff. A more complete discussion of similarvalve actions and constructions can be found in the above-mentionedQuarve patent. The fluid handling portion of the apparatus, in the caseof highly viscous plastic materials, must be maintained in a heatedcondition to preserve the desired viscosity of the particular fluidsbeing used, and, of course, the degree of heat will also be dependentupon these materials.

lt will be apparent from the foregoing that the method and apparatus ofthis invention provide solutions to many longstanding problems withinthe coating field. It is now possible through use of the invention (1 toaccurately spot-coat either sheet or weblike materials; (2) to uniformlyapply coatings in a wide range of thicknesses, and (3) to efficientlydeposit contoured or raised surface areas upon a substrate material.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

Iclaim:

1. Apparatus for forming a coating of material on a substratecomprising:

a. means for advancing said substrate along a path which carries asurface thereof past a device for depositing said material,

b. means for detecting an approaching area on said sub strate wheredeposition of said material is to begin,

c. a device positioned adjacent the path of the substrate for depositingmaterial on the surface of said substrate, said device comprising:

1. a nozzle manifold including a plurality of spaced aper turespositioned across the direction of advancement of said substrate throughwhich said material is adapted to flow and be deposited on the substratein a plurality of generally parallel beads,

2. means for forcing said material through said apertures in response todetection of the area to be coated, and 3. means for abruptlyterminating flow of said material through said nozzle aperturesincluding a displacement piston operable to decrease the pressure on theupstream side of said apertures relative to the environmental pressurein response to a given signal.

2. Apparatus according to claim I in which the apertures of said nozzleare substantially equally spaced.

3. Apparatus according to claim 1 in which the apertures of said nozzleextend substantially perpendicular to the direction of substrate travel.

4. Apparatus according to claim 1 which includes means for uniformlydistributing the coating on the substrate.

5. Apparatus according to claim 1 which includes means for imparting aparticular surface configuration to said coating.

6. Apparatus according to claim 4 which includes means for imparting aparticular surface configuration to said coating.

7. A method for applying a coating of material to a selected area ofsubstrate material which comprises the steps of a. advancing saidsubstrate along a path which carries a surface of said substrate past anapplicator for receiving an application of material,

b. detecting an approaching area on said substrate where application ofsaid material is to begin,

c. in response to detecting said area, initiating application of aplurality of substantially equal and substantially parallel beads of acoating material to said selected area of the substrate extending in thedirection of advancement of said substrate, and terminating applicationof said plurality of parallel beads by creating a pressure differentialat said applicator whereby discharge from said nozzle is abruptlyterminated.

8. A method according to claim 7 which includes the additional step ofsmoothing said beads to form a coating of substantially uniformthickness.

9. A method according to claim 7 which includes the additional step ofimparting a particular surface configuration to said coating.

10. A method according to claim 8 which includes the additional step ofimparting a particular surface configuration to said coating.

2. Apparatus according to claim 1 in which the apertures of said nozzleare substantially equally spaced.
 2. means for forcing said materialthrough said apertures in response to detection of the area to becoated, and
 3. means for abruptly terminating flow of said materialthrough said nozzle apertures including a displacement piston operableto decrease the pressure on the upstream side of said apertures relativeto the environmental pressure in response to a given signal. 3.Apparatus according to claim 1 in which the apertures of said nozzleextend substantially perpendicular to the direction of substrate travel.4. Apparatus according to claim 1 which includes means for uniformlydistributing the coating on the substrate.
 5. Apparatus according toclaim 1 which includes means for imparting a particular surfaceconfiguration to said coating.
 6. Apparatus according to claim 4 whichincludes means for imparting a particular surface configuration to saidcoating.
 7. A method for applying a coating of material to a selectedarea of substrate material which comprises the steps of a. advancingsaid substrate along a path which carries a surface of said substratepast an applicator for receiving an application of material, b.detecting an approaching area on said substrate where application ofsaid material is to begin, c. in response to detecting said area,initiating application of a plurality of substantially equal andsubstantially parallel beads of a coating material to said selected areaof the substrate extending in the direction of advancement of saidsubstrate, and d. terminating application of said plurality of parallelbeads by creating a pressure differential at said applicator wherebydischarge from said nozzle is abruptly terminated.
 8. A method accordingto claim 7 which includes the additional step of smoothing said beads toform a coating of substantially uniform thickness.
 9. A method accordingto claim 7 which includes the additional step of imparting a particularsurface configuration to said coating.
 10. A method according to claim 8which includes the additional step of imparting a particular surfaceconfiguration to said coating.